Creating Waves of Awareness
PREGNANCY AND THYROID DYSFUNCTION
Pregnancy and Hypothyroidism
Hypothyroidism is associated with menstrual irregularities and infertility. Hypothyroidism during pregnancy is almost always mild and almost always due to Hashimoto’s thyroiditis. It is very important to make the diagnosis early, as hypothyroidism has been associated with maternal and fetal morbidity.
Diagnosis of hypothyroidism is confirmed by an elevated TSH level. All the cases of pregnancy should be screened for hypothyroidism if they have a history of thyroid disease, goiter, other autoimmune disease, recurrent miscarriage, or family history of autoimmune thyroid.
During pregnancy, the thyroid hormone requirements in the majority of patients may increase up to 50%. The presence of antithyroid antibodies in the absence of thyroid dysfunction is associated with an increased risk for miscarriage.
Pregnancy and Hyperthyroidism
Many signs and symptoms of hyperthyroidism occur in normal pregnancy. Specific signs of hyperthyroidism are failure of the mother or fetus to gain weight, resting tachycardia, an enlarged thyroid gland, exophthalmos, lid lag, muscle weakness, diarrhea, or tremor.
The most common cause is Graves’ disease, which often has clinical exacerbations during the first trimester of pregnancy. Toxic multinodular goitre (MNG) is anuncommon cause. It usually occurs in women older than 40 yr with a history of MNG.
The diagnosis of hyperthyroidism during pregnancy is made by suppressed TSH with an elevated free T4 or free T3. Measurement of TPOAb can confirm the autoimmune nature of the thyroid dysfunction if other signs associated with Graves’ disease are not present. TSI is measured during the third trimester, because high titers increase the risk of fetal goiter and hyperthyroidism due to TSI transfer across the placenta. If the TSI is high, a third trimester fetal ultrasound should be considered to determine if the fetal goiter will prevent a vaginal delivery.
Hyperemesis gravidarum is associated with a low TSH without elevated thyroid hormone levels.
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